Ad blocking rates must be directly measured; other ways of estimating it based on counting downloads is not accurate. There are also differences between desktop versus mobile which should be broken out. Mobile ad blocking is on the rise due to the adoption of browsers that block ads and trackers natively.

1. January 4, 2018marketing.scienceconsulting group, inc.
linkedin.com/in/augustinefou
Jan 2018 Ad Blocking Update
Marketing Science analyzed over 3 billion pageviews from 30+ mainstream publishers in
the U.S. The data was directly measured in the month of December 2017. Mobile means
mobile web and includes phones and tablets. Non-mobile means desktop and laptops.
The methodology includes the following:
• Not measured - on average 8-9% of the pageviews could not be measured for ad
blocking (e.g. browser did not run javascript, measurement script blocked etc.).
• Bots must be scrubbed - on average, good publishers had 1 - 4% bots (NHT, IVT),
which were scrubbed from the data. Bots do not block ads and therefore should not
be counted.
• Confirmed by direct measurement - of the remaining pageviews, ad blocking was
measured by calling an ad – ad.gif, with standard dimensions – 300x250. The results
were adblock:1 (“ad blocked”) or adblock:0 (“not ad blocked”).
KEY FINDINGS
1. In the U.S. ad blocking in mobile is now between 0.2 – 0.5%, up from
0%; this is due to ad blocking built into browsers, like Opera and
Safari; also Firefox has tracking protection (writebacks are stopped)
2. Ad blocking by users visiting b2b sites (5.8% average) is slightly higher
than visitors of consumer sites (4.3% average); likely due to the use of
devices managed by offices or universities, versus personal devices.
3. Ad blocking rates with bots excluded remains close to overall average
ad blocking rates because the publishers measured had low bots.
4% ad blocking on desktop
(range was 2-7% blocking)
6% ad blocking on desktop
(range was 3-11% blocking)